Network Render addon compositing issue
Tracking things down led to client.py line 354

class NetworkRenderEngine(bpy.types.RenderEngine):
    bl_idname = 'NET_RENDER'
    bl_label = "Network Render"
    #bl_use_postprocess = False
    bl_use_postprocess = True #turning this to true enabled the blur and layer mask issue (not yet discussed)


I think the network render is a great feature, but could use some optimization. Seems to be a lot faster if you can use a shared directory, placeholders approach with no overwrite, and start multiple instances of blender on multiple machines (pretty fast renders). Cons: no management, oversight, and then have to manually put everything together at the end. Which is why I wanted to use Network Render since it has those features.  Might end up needing to custom scripts to maximize speed or integrate multiple calls to background blender render processes (not sure how to do that offhand from the given code)--if anyone has any thoughts on this, please forward them my way.